River Syfynwy (Welsh: ''Afon Syfynwy'', ''Syfnwy'' or ''Syfni'') is a river entirely within

Pembrokeshire Pembrokeshire ( ; ) is a Principal areas of Wales, county in the South West Wales, south-west of Wales. It is bordered by Carmarthenshire to the east, Ceredigion to the northeast, and otherwise by the sea. Haverfordwest is the largest town and ...

Wales Wales ( ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by the Irish Sea to the north and west, England to the England–Wales border, east, the Bristol Channel to the south, and the Celtic ...

, rising in the

Preseli Mountains The Preseli Mountains (, ; or ), also known as the Preseli Hills, or just the Preselis, are a range of hills in western Wales, mostly within the Pembrokeshire Coast National Park and entirely within the county of Pembrokeshire. The range ...

, feeding the Rosebush and

Llys y Fran A royal court, often called simply a court when the royal context is clear, is an extended royal household in a monarchy, including all those who regularly attend on a monarch, or another central figure. Hence, the word ''court'' may also be ap ...

reservoirs and joining the

Eastern Cleddau The River Cleddau () consists of the Eastern and Western Cleddau rivers in Pembrokeshire, west Wales. They unite to form the Daugleddau estuary and the harbour of Milford Haven Waterway. The name of the combined estuary – the Daugleddau – ...

to the south. It is a river considered to be important as an ecological indicator and part is in a

site of special scientific interest A Site of Special Scientific Interest (SSSI) in Great Britain, or an Area of Special Scientific Interest (ASSI) in the Isle of Man and Northern Ireland, is a conservation designation denoting a protected area in the United Kingdom and Isle ...

Course

The river is formed by the confluence of several streams rising in the southern slopes of the Preseli Hills at some and flows southwards into Rosebush Reservoir, where it passes through or over the dam. Cascades, Syfynwy Falls, are immediately below the dam and are a visitor attraction when the reservoir is overflowing. Continuing south west, the river flows through a wooded valley - Holmus Wood, Farthing's Hook Wood and Dan-y-Coed, then under the Grade II-listed Farthing's Hook Bridge. It runs between Pen-yr-Allt Wood and Velindre Wood before entering the northern end of Llys y Fran reservoir. This reservoir's dam produces electricity. After the dam, the river flows in a more southerly direction before turning south east, passing under Step-aside Bridge, near Clarbeston, and the 18th century Grade II-listed Gelli Bridge at Gelli Hill to meet the Eastern Cleddau. The river is approximately long.

Ecology

The river has been used by some researchers as an indicator of ecological health and is included in the

River Cleddau The River Cleddau () consists of the Eastern and Western Cleddau rivers in Pembrokeshire, west Wales. They unite to form the Daugleddau estuary and the harbour of Milford Haven Waterway. The name of the combined estuary – the Daugleddau � ...

catchment area's Site of Special Scientific Interest (SSSI) for its wide range of indigenous wild plants and animals, including

water crowfoot ''Ranunculus'' is a large genus of about 1750 species of flowering plants in the family Ranunculaceae. Members of the genus are known as buttercups, spearworts and water crowfoots. The genus is distributed worldwide, primarily in temperate an ...

lamprey Lampreys (sometimes inaccurately called lamprey eels) are a group of Agnatha, jawless fish comprising the order (biology), order Petromyzontiformes , sole order in the Class (biology), class Petromyzontida. The adult lamprey is characterize ...

and

otter Otters are carnivorous mammals in the subfamily Lutrinae. The 13 extant otter species are all semiaquatic, aquatic, or marine. Lutrinae is a branch of the Mustelidae family, which includes weasels, badgers, mink, and wolverines, among ...

. The Syfynwy is included in the Eastern Cleddau Special Area of Conservation (SAC). In 2009 the Bro Syfynwy Heritage Group were granted £2,750 to produce a leaflet covering rural and historical life around the upper Syfynwy. The Llys y Fran Catchment Project is an ecological study based on the Afon Syfynwy catchment from its source to the Llys y Fran dam. The study, begun in July 2014, is focussed on understanding the blue green algae blooms that have been occurring in the reservoir and, with the support of landowners, will involve soil sampling and nutrient management. The project is being run in collaboration with

Welsh Water Welsh may refer to: Related to Wales * Welsh, of or about Wales * Welsh language, spoken in Wales * Welsh people, an ethnic group native to Wales Places * Welsh, Arkansas, U.S. * Welsh, Louisiana, U.S. * Welsh, Ohio, U.S. * Welsh Basin, during t ...

and

Natural Resources Wales Natural Resources Wales () is a Welsh Government sponsored body, which became operational from 1 April 2013, when it took over the management of the natural resources of Wales. It was formed from a merger of the Countryside Council for Wales, E ...

(NRW). As well as farming, the project will also consider the impact of sewage and forestry on the study area as well as water quality and invertebrate populations. Over the winter of 2013-14 Pembrokeshire Rivers Trust monitored riverflies at Gelli Bridge as part of a wider study of the Eastern Cleddau catchment area. They found fewer numbers than usual, but that most sensitive species were present.

Pollution

A pollution incident in 1999 where trade effluent was discharged into the river causing the death of an estimated 1,000 brown trout resulted in a fine of £2,500 and £13,021 costs when the case went to court the following year.

World War 2

During the war the railway at Glan Syfynwy, near Rosebush, was used for bombing practice by the RAF and USAF.

References

External links